This invention relates to an apparatus for grinding materials such as branches, leaves, twigs or the like to reduce the size of the material, and to thereafter discharge the ground material.
With increasing environmental concerns and landfill problems, many municipalities strictly limited the manner in which yard waste such as branches, leaves, twigs or the like can be disposed. It is not uncommon for a municipality to altogether ban the presence of such material in conventional refuse pick-up, and to require that such material be disposed of in accordance with strictly enforced regulations.
Accordingly, it has become necessary for a homeowner to take a more active role in disposal of yard waste material. Many homeowners comply with local regulations pertaining to disposal of yard waste material by placing such material in a separate receptacle for pick-up, or by carrying such material to an approved site for disposal.
In view of the above, there exists a need for a device which a homeowner can employ to assist in disposal of yard waste material. While conventional chipper/shredders are often owned and used by serious gardeners and/or homeowners with larger properties, such machines are generally fairly expensive and have a much greater capacity than is needed by most homeowners.
It is an object of the present invention to provide an apparatus for processing yard waste material such as branches, leaves, twigs or the like, which is relatively less expensive to produce than a conventional chipper/shredder, and which accordingly can be afforded by a greater number of homeowners. It is another object of the invention to provide an apparatus for processing yard waste material which is light in weight and compact in shape, which therefore is easy to use and store. It is a further object of the invention to provide such an apparatus which is relatively simple in its construction and operation, yet which provides highly efficient grinding of yard waste material to effectively reduce its size prior to disposal or use of the ground material as mulch.
In accordance with one aspect of the invention, an apparatus for processing yard waste material comprises a grinder housing which defines a grinding chamber having an inlet through which unprocessed material is introduced into the grinding chamber. The apparatus further includes a fan housing defining a fan chamber located adjacent the grinder housing, with the fan chamber including an outlet through which processed material is discharged. The grinding chamber and the fan chamber are in communication with each other. A rotatable grinding mechanism is located within the grinding chamber, to grind material introduced into the grinding chamber upon rotation of the grinding mechanism. A rotatable fan mechanism is located within the fan chamber. Rotation of the fan mechanism generates negative air pressure within the fan chamber to draw ground material from the grinding chamber into the fan chamber. The rotatable fan mechanism and the fan chamber cooperate to define an arcuate discharge flow path to which ground material is supplied from the grinding chamber. At least a portion of the discharge flow path experiences positive air pressure during rotation of the fan mechanism, to move the ground material toward the fan chamber discharge outlet. The grinding mechanism and the fan mechanism are preferably connected together and rotatable with each other, and are rotatably driven in response to rotation of a rotatable output shaft associated with a rotary power source, such as a conventional gasoline or electric engine. The fan mechanism and the grinding mechanism are mounted side-by-side on a rotor assembly rotatable about a rotor axis, with a portion of the rotor assembly being located within the fan chamber and a portion located within the grinding chamber. The rotor assembly consists of a pair of spaced plates interconnected through a series of shafts, with one of the plates being located in the fan chamber and the other of the plates being located in the grinding chamber. The fan mechanism includes a series of fan blades, which are interconnected with one of the plates. The grinding mechanism includes a series of hammers pivotably mounted to the shafts which extend between the pair of plates. The hammers are located adjacent an arcuate inner wall defined by the grinder housing, and one or more projections are provided on the grinder housing inner wall for engaging the material to facilitate grinding of the material by the hammers. The fan chamber and the grinding chamber are separated by a wall, with an opening being formed in the wall to allow passage of ground material from the grinding chamber into the fan chamber. A series of spaced scallops are provided in the opening for providing passage of ground material into the fan chamber. The ground material is drawn through the scallops into the fan chamber by the negative air pressure generated by rotation of the fan mechanism, after the particles of material are ground to a sufficiently reduced size or weight to allow the particles to pass through the scallops. A hopper structure is connected to the grinder housing, and defines a passage through which unprocessed material is supplied to the grinder housing inlet. In a preferred form, a second inlet is formed in the grinder housing, and a vacuum hose is connectable through a connector assembly with the grinder housing. Various attachments can be secured to the outer end of the vacuum hose, such as a leaf tray into which leaves can be raked, or a nozzle to allow leaves or other debris to be sucked from areas which are difficult to reach with a rake. The apparatus further includes a chipper assembly, consisting of one or more chipper knives mounted to a chipper plate, to which the fan blades are secured. The fan housing is provided with a chipper opening over which the chipper knives pass upon rotation of the fan mechanism, and branches can be passed through the chipper opening for chipping by the chipper knives. The branch chips are then conveyed through the fan housing by the positive air pressure generated by rotation of the fan mechanism, to the fan housing discharge outlet. The arcuate discharge flow path defined by the fan mechanism and the fan chamber comprises a scroll having an increasing transverse dimension in the direction of rotation of the fan mechanism, toward the fan housing discharge outlet. This arrangement provides highly satisfactory conveying of ground or chipped material within the fan chamber toward the fan chamber discharge outlet.
In accordance with another aspect of the invention, the hopper defines a cavity, which communicates through a substantially vertical passage with the inlet to the grinder housing. A guard member is located within the hopper cavity in vertical overlapping relationship with the passage through which the hopper cavity communicates with the grinder housing inlet. The hopper is constructed so as to define a flow path for the unprocessed material, around the guard member and leading to the passage. With this arrangement, the passage is blocked in a vertical direction, so as to prevent kickback of the material upwardly out of the hopper cavity from the passage. The hopper preferably includes a curved wall defining a portion of the hopper cavity, with the curved wall being spaced from an material along the curved wall during operation.
In accordance with yet another aspect of the invention, the grinder housing and the fan housing comprise an assembly which defines a pair of spaced vertical mounting surfaces, with the grinding mechanism and the fan mechanism being rotatable about a substantially horizontal axis of rotation and being driven by a power source having a horizontal output shaft. The hopper is mounted to one of the spaced vertical mounting surfaces, and the power source is mounted to the other of the vertical surfaces. This arrangement provides a compact overall package for the yard waste material processing apparatus. A chipper assembly is provided, and includes a chipper knife which passes over a chipper opening formed in one of the vertical mounting surfaces. A chipper chute is mounted to the same vertical mounting surface, and defines an internal passage communicating with the chipper opening.
Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings.